What Size Furnace Do I Need?

If you aren’t sure about the furnace size your Triangle home needs, you’re at the right place. It is not a simple matter with a simple answer, and North Carolina Heating & Cooling is glad to help! The heater capacity is measured in BTU, the British Thermal Unit, indicating the energy needed to get the temperature of 1 lb of water up by 1° F.

No. 1: The Size of the Home

The main factor in determining your ideal furnace is the square footage of the home. Most houses require 30 to 60 BTU per square foot in the US. So, for example, the standard 2,000 sq. ft. location will require anywhere from 60,000 to 120,000 BTU regarding the age of the house, building code requirements, insulation, fireplace or not, and more.

But why does that number vary by as much as 30 BTU to begin with? That’s where the second part of the equation steps in, the climate zone.

No. 2: The Climate Zone

The second piece of info you will need to determine the best heater for you is the climate zone you are in. The US is split into seven zones; Zone 1 is the warmest, while Zone 7 is the coldest. For example, Texas is mostly Zone 1, while Maine is mostly Zone 7. Zone 1 is 30 BTU, while Zone 7 is 60. A heat pump will do the trick in Zone 1, 2, and 3, while the higher zones require a furnace. North Carolina is split between climate Zones 3 and 4 near Raleigh, so your zone may vary. Consult a professional for more information. 

And as you might have guessed, the total BTU required is calculated simply by multiplying the square footage of the home with the climate zone factor.

In fact, it is more complicated than that and it requires a load calculation

We will take care of that for you and once you have the number, you can find the top furnace to deliver the heat.

Note that the exact number can still vary based on the age and construction of your home, the windows, and more. For the most accurate info, it’s always the best solution to consult a qualified HVAC professional like NCHC.

If you’re looking for the best furnace seller in Raleigh and Durham, NC, you know where to find us!